Certificate Transparency Go

certificate-transparency-go is a Go codebase for building and interacting with Certificate Transparency (CT) systems, from low-level parsing to full log operation. It includes forked ASN.1 and X.509 packages tailored to accept and analyze real-world certificates, including pre-certificates that stricter libraries would reject, supporting CT’s role as an ecosystem observatory. A TLS parsing library, CT data types, and multiple client libraries enable access to CT logs over HTTP and DNS, along with scanners for traversing entire logs. The repository also provides command-line tools for verifying signed certificate timestamps, inspecting certificates and CRLs, and querying logs. For operators, a “CT personality” integrates with Trillian so you can run a CT log backed by a verifiable transparency log. The project is structured for contributors, with generators, mocks, linting, and presubmit tooling to keep changes consistent and reliable.